Ballast removal process

ABSTRACT

Old ballast is removed from under a section of railway track with a bulldozer having an elongated rake attached to its front blade. The section of railway track is first elevated. The bulldozer is then driven along the section with its rake extending under the section and at a level that causes old ballast to be swept from under the section.

FIELD OF THE INVENTION

This invention relates to railways. More particularly, this invention relates to a process for removing railway ballast.

BACKGROUND OF THE INVENTION

Railways consist of track (two parallel steel rails attached to transverse wooden ties) that rests upon a base of crushed rock known as ballast. The ballast serves several purposes. Its primary purpose is to provide an easily leveled base for the track. Additional purposes are achieved because the ballast is compressible. The compressibility provides cushioning as the train passes, accommodates the expansion and contraction of the track at temperature extremes, and avoids vertical movement caused by freeze-thaw cycles.

Fine materials from coal, grain, and other bulk solids frequently leak from railroad cars. Over time, these fine materials build up in the ballast directly under the tracks. The presence of these fine materials reduces the compressibility of the ballast. Accordingly, it is necessary to periodically replace the upper portion of the ballast.

The conventional process for replacing ballast is to first elevate a section of the track. The upper portion of the old ballast is then swept aside using a special machine that travels along the elevated track with a scraper or blade that reaches around and under the track. The track is then lowered and new ballast is poured between the rails and into the spaces between the ties. Ballast removing machines are disclosed in Walbridge, U.S. Pat. No. 1,929,617, Oct. 10, 1933; and Moss, U.S. Pat. No. 3,055,309, Sep. 25, 1962. The Walbridge and Moss machines are expensive and are not suitable for any use than the removal of old ballast.

A machine designed for grading the ballast to the side of the tracks is disclosed in Burns et al., U.S. Pat. No. 2,491,797, Dec. 20, 1949. The Burns et al. machine is not suitable for removing ballast from under the track. A machine designed for grading earth along a trench or ditch is disclosed in Hurworth, U.S. Pat. No. 4,953,625, Sep. 4, 1990. There is no teaching or suggestion of using the Hurworth machine to remove ballast from under a track.

Accordingly, there is a demand for an improved process for removing old ballast from under a section of railroad track. More particularly, there is a demand for such a process that is fast, is not labor intensive, and uses a machine that is suitable for other uses.

SUMMARY OF THE INVENTION

The general object of this invention is to provide an improved process for removing old ballast from under a section of railroad track. A more particular object is to provide such a process that is fast, is not labor intensive, and uses a machine that is suitable for other uses.

I have invented process for removing old ballast from under a section of railway track. The process comprises: (a) obtaining a bulldozer having an elongated rake, attached to its front blade, the rake extending outwardly from the side of the bulldozer; (b) elevating a section of railway track; and (c) driving the bulldozer along the section of elevated track with its rake extending under the section and at a level that causes old ballast to be swept from under the section.

The ballast removal process of this invention is fast, is not labor intensive, and uses a machine that is suitable for other uses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the process of this invention.

FIG. 2 is a detailed front perspective view showing the attachment of the rake to the blade used in the process.

FIG. 3 is a detailed rear perspective view thereof.

DETAILED DESCRIPTION OF THE INVENTION

This invention is best understood by reference to the drawings. Referring to FIG. 1, a section of railway track consisting of rails 10 and ties 20 (only portions of which are shown for clarity) is elevated above a bed of ballast 30 by two railway jacks 40 that are spaced about 50 to 200 feet apart. Suitable railway jacks are well known in the industry and are available from many different manufacturers.

A bulldozer 50 having a front blade 60 is positioned alongside the section of elevated railway track. The position of the blade is controllable by the operator from inside the cab. The bulldozer is conventional except for an elongated rake 70 attached to the front blade. The means for attachment 80 is a matter of choice and can be permanent (e.g., the rake can be welded to the blade) or temporary (i.e., the rake is able to be attached to and removed from the blade in a relatively short time). The means for attachment is preferably temporary so the bulldozer can be used in a conventional manner without the rake when desired.

Referring to FIGS. 2 and 3, a preferred temporary means of attachment includes an upper bracket 61, a face bracket 62, and a side bracket 63 welded to the blade. The means of attachment also includes a spacer fitting assembly 71 and a rear bracket 72 welded to the rear of the rake. The spacer fitting assembly includes a top bracket 73 and a side bracket 74. The blade and the rake are attached by making three connections: (1) an upper turnbuckle 81 between the upper bracket of the blade and the upper bracket of the spacer fitting assembly; (2) a side turnbuckle 82 between the side bracket of the blade and the rear bracket of the rake; and (3) a pin connection 83 between the face bracket of the blade and the side bracket of the spacer fitting assembly. Certain components are omitted from FIG. 2 and FIG. 3 for clarity. For example, FIG. 2 omits the side bracket on the blade and the side turnbuckle while FIG. 3 omits the top bracket on the blade and the spacer fitting assembly.

The rake is preferably about ten to sixteen feet in length and about one to two feet in height with a curved (concave) surface. It is not necessary for the rake to move independently of the blade. However, if desired, the means for attachment can include hydraulic cylinders or the like combined with controls to enable movement of the rake independently of the blade. A suitable bulldozer is the Caterpillar model D5 bulldozer manufactured and sold by Caterpillar Inc. of Peoria, Ill.

Referring again to FIG. 1, to remove old ballast from under the section of track, the bulldozer is driven alongside the track. The operator adjusts the position of the blade so the rake sweeps the desired depth of ballast to the side of the track. The old ballast can then be left in place or removed.

After the old ballast has been swept from under the section of elevated track, the jacks are used to lower the section back down to the ballast. A rail car carrying new crushed rock is then brought to the section. The new crushed rock is then dumped and distributed between the rails. The new crushed rock restores the compressibility of the ballast. The process is then repeated at the next section of track.

The ballast removal process of this invention is fast and can be performed with a minimal number of workers. The bulldozer used in the process is of a type that is widely available and is suitable for many uses.

The ballast removal process is modified as necessary if the removal and replacement of more or less ballast is desired. For example, if more ballast is to be replaced, a load of crushed rock is unloaded at the site after the upper layer of old ballast has been removed. The new crushed rock is then spread under the section of elevated track to the desired level. The track is then lowered and additional new crushed rock is dumped and distributed between the rails. 

1. A process for removing old ballast from under a section of railway track, the method comprising: (a) obtaining a bulldozer having an elongated rake attached to its front blade, the rake extending outwardly from the side of the bulldozer; (b) elevating a section of railway track; and (c) driving the bulldozer along the section of elevated track with its rake extending under the section and at a level that causes old ballast to be swept from under the section.
 2. The process of claim 1 wherein the elongated rake is temporarily attached to the front blade of the bulldozer.
 3. The process of claim 2 wherein the section of railway track is elevated by railway jacks spaced apart by about 50 to 200 feet.
 4. The process of claim 3 wherein the rake is about ten to sixteen feet in length and about one to two feet in height.
 5. The process of claim 4 additionally comprising the steps of: (d) lowering the section of railway track; and (e) dumping and distributing new crushed rock over the section. 